<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0" user-scalable="no">
    <title>Document</title>
    <style>
        .box{
            width: 200px;
            height: 200px;
            background-color: red;
        }
        .box1{
            width: 100px;
            height: 100px;
            background-color: yellow;
        }
    </style>
</head>
<body>
    <div class="box" name="ma">
        <div class="box1"></div>
    </div>


    <script>
        
        console.log(document.getElementsByName('ma'));
        var  box=  document.querySelector('.box')
        var box1=  box.getElementsByClassName('box1')[0]
        console.log(box1,'???/。');
    </script>
</body>
</html>